Acer Laptop screen problem 16:10 change to 4:3

Hi,
My problem is my acer travelmate 4200 screen is now showing only 1024 x 768 (4:3) there are black boder on right side of the screen that doesn't show anything.

The back lighting in that area is normal. my laptop is 15 inch and the native resolution is 1280 x 768 but when i check the Hide mode that monitor doesn't support option it only display 800 x 600 and 1024 x 768 only.

I already update the BIOS and the graphic driver but the problem still remain. I search the internet and found that i problem may be due to epresentation.I update the epresentation and the problem persist.

I also remove the connect the LCD connector to the motherboard but the screen stay the same.

So can anyone help me.

 

What is your videocard? Intel? Go to Intel Graphic Media Accelerator control panel->Display Settings->Aspect Ratio and select Full Screen(No border). If that don't help and 'Full Screen' is already selected I'd try reinstall the driver.

 

I already tried that but it don't work any other suggestion